This invention relates to a pressure transducer in general and more particularly to an improved pressure transducer of the type with a deformation body of single-crystal semiconductor material, which is provided, in a thin central region serving as a diaphragm, with a resistor arrangement, the resistance change of which is a measure for the pressure.
Pressure transducers of this type in which the resistors therefore serve as strain measuring strips and are provided with electrical contacts are known.
Planar technology can be used for making the resistor arrangement. The wafer-like semiconductor body, the flat side of which is preferably parallel to the (111)-plane of the crystal, is provided with diffused-in electrically conducting regions at its surface which serve as strain measuring strips and can advantageously form four resistors in a bridge circuit. This resistor arrangement can advantageously form a monolithic surface region of the semiconductor body and is provided with electrical contacts. The curvature and thereby, the resistance both change with the pressure. The resistance change changes the voltage at the bridge. (Philips Technische Rundschau 33, 1973/74, no. 1, pages 15 to 22).